Strain Rate and Temperature Effects on the Strength and Dissipative Mechanisms in Al-Cu50Zr50 Interface Model: Molecular Dynamics Simulation Study

Abstract

Molecular dynamics (MD) simulations are performed to characterize the metal (Al)-metallic glass (Cu50Zr50) interface strength and dissipative mechanisms at different strain rates and temperatures under mode-I loading. EAM (Embedded Atom Method) potential is used for modelling the interaction between Al-Cu-Zr atoms. Simulation box size of 100Å (x) × 110Å (y) × 50Å (z) is used for investigation the properties of the model interface. The model is first constructed with the bottom layer Al of 50Å and the top layer of Cu50Zr50 of 55Å in height along y–direction. Thereafter, Cu50Zr50 metallic glass is obtained by rapid cooling at a cooling rate of 8.5 × 1011 K s-1 using NPT ensemble. The interface is deformed at strain rates of 109 s-1 and 1010 s-1 and at temperatures of 150K and 250K using NVT ensemble (timestep=0.002 ps). It is found that the strength of interface increases with increase of strain rate and decreases with increase in temperature. Centro symmetry parameter (CSP) is used for analysis of dissipative mechanisms operative during the deformation of the interface. It is found that the dominant deformation mechanism at the interface is by Shockley partial dislocation motion.